Web search is an important activity in daily life for many individuals. Individuals use queries to characterize topics of interest and then gain information from the Web on those topics. For convenience, and sometimes necessity, users of the Web prefer to deliver a query in voice and expect a search engine return web results with respect to the voice query. Typically, search engines which are able to accept a voice query, have a voice interface (or a speech-to-text system) which converts the voice query to a text query; then a standard text search engine produce results with respect to the text query.
In voice search systems having a traditional text search engine augmented with a speech-to-text based voice interface, the misrecognition of voice queries by the speech-to-text system is a formidable obstacle, often leading to completely irrelevant search results. Typically, a speech-to-text system has a predefined “vocabulary” or a list of words, which the system can recognize. A word outside of this list is an out-of-vocabulary (OOV) word and cannot be recognized, instead being recognized as word in the predefined vocabulary. In the field of web search, where new phrases and names are constantly introduced, the chances of a user uttering an OOV word in a voice query are very high. In the past, enlarging the predefined vocabulary was used to slightly mitigate the misrecognition caused by OOV words. However, up to certain extent a very large vocabulary makes a speech-to-text system impractical. Therefore, a need exists for a method and apparatus for generating a text query from a voice query, which is not limited by any predefined vocabulary.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. Those skilled in the art will further recognize that references to specific implementation embodiments such as “circuitry” may equally be accomplished via replacement with software instruction executions either on general purpose computing apparatus (e.g., CPU) or specialized processing apparatus (e.g., DSP). It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.